Crystals have constant angles because of the regular arrangement of its particles. There are seven types of crystals: cubic, tetragonal, orthorhombic, hexagonal, trigonal, monoclinic, and triclinic (Dr. Boyle). Crystals are classified by the shapes of their lattice or the ?regular, periodic configuration of particles? (American Heritage). There are two different types of lattices.
There are three F’s on how fractures happen. The first one is fall the way you fall or get injured. The second f is force, the force and direction of the fall. And the final F is fragility, the fragility of the bone that takes the impact. The prevention and treatment of fractures is important to overall health, but there are various treatments available of a fracture.
It is more difficult to determine the precise structure of glass than that of crystalline solid. The structure of glass lacks translational symmetry, so that, it is impossible to define a unit cell. The absence of periodicity and symmetry in glass distinguishes it from a crystal. The isotropic vibration properties of glass are consequence of absence of symmetry and the atomic arrangement should be statistically the same in all directions. The structure of TeO2- based glasses is also of interest, because there are two types of basic structure unit, namely TeO4 trigonal bipyramids (tbp) and TeO3 trigonal pyramid (tp) as shown in figure below (Ayuni et al., 2011, Biirger et al.,
Priestley (1997) and Hakuto et al. (2000) suggested the principle tensile stress approach to calculate the joint shear strength without joint shear reinforceemnt. Attalla (2004) presented a theorotical model considering the compression-softening phenomenon associated with the cracked reinforced concrete in compression. The effect of joint geometry and the presence of transverse beams are also consiered on joint shear strength. A fifth order polynomial equation was proposed by Tsonos (2002 and 2007) to find the ultimate joint shear strength.
The severity of a fracture is usually determined by the force that caused the break. The bone may fissure rather than break all the way through, if the breaking point of the bone has been exceeded only slightly. If the force is much more than the breaking point, such as in an automobile crash or a gunshot, the bone may splinter into pieces. If the broken bone punctures the skin, it leads to an open or compound fracture. Fractures commonly caused
. Depending upon dispersed phase and dispersion medium, there are eight types of colloidal solutions: Classification of colloids Depending upon type of interaction betwwen dispersed media and dispersed phase there are two classes of colloids Hydrophilic colloids : These are water loving colloids easily spread throughout medium and are easiy to prepare .these colloids are stable because there are strong forces of interaction between colloidal particles and liquid These are also called Reversible colloids because on evaporating the liquid, the residue left will passes into colloidal state on addition of liquid. Examples: agar is a reversible hydrocolloid of seaweed extract; it can exist in a gel or liquid state and can alternate between states with either heating or cooling. proteins -nucleic acids -micelles of soaps also form hydrophilic colloids hydrophobic colloids: These colloids, also known as emulsion are water repellent and lack the tendency to mix with water so are difficult to prepare. As there are weak forces of intearaction between water and particles so these are unstable
The concrete stress increases with distance from the crack, due to the steel-concrete bond, until at some distance from the crack, the concrete stress is no longer affected by the crack, as shown in Figure 1(b). Slip at the concrete-steel interface in the region of significant bond stress causes the crack to open. The concrete stress increases with distance from the crack, due to the steel-concrete bond, offering some resistance to the applied load, which is the ‘Tension Stiffening’ effect in
According to Grobler etl[5], selected a cut level of CT through the superior vertebral end-plate of the lower vertebra and parallel to the inferior vertebral end-plate of the superior vertebra , then three lines (line a,b,c)were marked ,among them, line a is the tangent through trailing edge of the vertebral body and line a,b through anteromedial and posterolateral point of the corresponding facet joint respectively. Angle ab and angle ac(Figure 1) as the corresponding facet joint angle were recoded. Tropism The definition of tropism is first proposed by Brailsford JF[12] .It refers to the asymmetry of bilateral facet joint, the absolute value of the angle difference of bilateral articular facet joint as the tropism quantitative value Pfirrmann grading Intervertebral disc was classified into gradeⅠ- Ⅴ (图2) by Pfirrmann et al [13] based on image of sagittal MRI T2-weighted images（图3） The angle of the facet joint was measured by two independent individuals. If the difference between the two data does not exceed 2 degrees, the average of the two measurements is taken as the angle of the corresponding facet joint. If, on the contrary, the two measured values differ by more than 2 degrees, repeat the measurement until the standard is
This is because I find the wrong point of stress and strain and influences the data of extension. In details, I shouldn’t find the points in the strain which are more than 0.4mm/mm, because the mild steel was broke when the strain after 0.4mm/mm, no elongation occurs and therefore, no extension occurs. Other than that, at the beginning of the lab test, we did not measure the mild steel accurately. If we are able to measure it precisely, the break of the mild steel will be horizontally straight. Furthermore, the mild steel is manufactured by machine and we cannot account that each and every mild steel have the same length and mass.
Stress is the psychological either strain or distress resulting from exposure to unusual or demanding situations, known as stressors. Meanwhile, job stress is the response to organizational stressors in the workplace environment that pose as a perceived threat to an individual’s well-being or safety. Individual level factors have also been implicated in stress outcomes, both as contributing factors as well as moderators of stress (Finney, et.al, 2013). Job stress is a common occurrence among various professions worldwide, is regarded as a major occupational health problem for health care professionals especially teacher. Job stress has been reported to affect job performance among teacher as they might become less competitive and low commitment.